The Neuropathology Core serves many critical functions in the Mount Sinai Alzheimer's Disease Research Center (ADRC). It coordinates a network of facilities to expedite the acquisition of postmortem brain tissue specimens from patients who die with a clinical diagnosis of Alzheimer's disease (AD) and from appropriate nondemented control individuals. It performs neuropathologic evaluation and characterization of those brain tissues to insure diagnostic accuracy and suitability for the large number of complex biochemical and molecular biological procedures associated with the scientific activities of the ADRC. The core provides a means for the further characterization of the extent and distribution of a variety of neuropathologic and neurochemical alterations associated with AD, thus adding a critical element to the ADRC data base. @Finally, it attempts to correlate these neuropathologic and neurochemical changes with antemortem clinical, psychometric, psychopharmacologic, and neurochemical data obtained from patients followed longitudinally by the ADRC.